Fish tank virtual reality (FTVR) has been defined in Ware, C., Arthur, K., and Booth, K. S. 1993 “Fish tank virtual reality” in Proceedings of the INTERCHI '93 Conference on Human Factors in Computing Systems (Amsterdam, The Netherlands). S. Ashlund, A. Henderson, E. Hollnagel, K. Mullet, and T. White, Eds. IOS Press, Amsterdam, The Netherlands, 37-42.
FTVR is a virtual reality system consisting of a display device coupled with suitable face-tracking hardware and/or software component such that the image shown on the display device is transformed in direct response to changes in the observer's point of view in order to provide the illusion of parallax. The changes to the observer's point of view are detected by the face-tracking device and fed into the rendering engine which in turn alters the position and angle of the virtual camera, resulting in a new image of the scene from the new vantage point being displayed on the display device. Experiments have shown that FTVR improves the ability of humans to comprehend 3D objects represented on flat 2D display devices.
Known systems for FTVR do not describe how to support FTVR using existing unmodified applications that use industry standard 3D APIs such as OpenGL (OpenGL is a trade mark of Silicon Graphics, Inc.), DirectX (DirectX is a trade mark of Microsoft Corporation) or OpenGL ES (OpenGL for Embedded Systems). This is a drawback with existing FTVR systems because it means that only the users of applications written specifically to include FTVR functionality can experience the benefits of FTVR.